Light-responsive commutator or switchboard



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M. E. GOULD Filed Nov. 9, 1957 s sheets-sheet 1 f 1 1H HV 1 1 mw ,WM MMM AMM uw Hs@ 1 w .1 1%@ 11 1R 1\ v@.11.1.21..k QN www. QN QN 1&1 .weh ...d 10A *o* In* Qua vo* ai 1a. van 1.... v fvv uw vwvwvw iii,... 1 1 *omini 1u* 1...*v ,mw @N s... @L #a 121 v.. d. wfi .11, Qmkgw @MILF Feb. 6, 1940.

LIGHT-RESPONSIVE coMMUTAToR oP. swITcHBoARD Feb. 6, 1940. M. E. GOULD LIGHT-RESPONSIVE COMMUTATOR OR SWITCHBOARD 3 Sheets-Sheet 2 Filed Nov. 9, 1957 mi@ if Gauzd Feb. e, 1940. l M. E, GQULD 2,139,001

LIGHT-RESPONSIVE COMMUTATOR OR' SWITCHBOARD Filed Nov. 9, 1937 3 Sheets-Sheet 3 ,Z/Ze E Gould Patented Feb. 6, 1940 *l UNI'IVE-.Dr PATENT OFFICE 2,189,001 o 1 J HGn'rfnEsPoNsryE coMMU'rA'ron on n swrrcnBoAnD l l Merle E.Gonld, Wlifite Plains, N. Y., assigner to `Plrotoele`ctric Business Machines, Inc., Washington,' D. C., a eorporationjof Delaware' Application November 9, 1937, A sonni No. y173,726v

This invention relates' for .selecting one at a time of a plurality of signalling lines to carry current lindicative of certain types or oriy gins of data and' further to break'. up the data. "5f into its components for the recording or tabulating of the components.;

It isgan important objectv offthis invention tofprovide means Wherebya production report, for instance, may .be inspected by light-responsive means according to a classified division or subdivision and have its components in' thisdivision or subdivisionl scanned by light-responsive l means and recorded. f 1

' Itis a further object oi this invention to 'provide light-responsive units in coded position and actuable by beams of light in coded position to select one at a time of a group of signalling lines to carry current and be' indicative of the coded positionv of the activated lighteresponsive units.

and actuablerby beams'of light' in coded position to energize selectively certain selected currentresponsive devices ofl a plurality 4of such devices,

25 the current-responsive devicesso selected by said light-responsive units being then actu'able" to condition'other devicesA for actuation by Vcoded light-responsiveunits actuated by beams of light in coded position. f v v It is a further object of this invention to provide `light-responsive units in coded position and actuable by beams of light in'coded position to select one at a time of a group v4of signalling lines for energization of the selected line, and to pro'- vide means for selectively de-energizing the line selected forenergization. y l

It is a further object of this invention to prof vide light-responsive units .in coded position and momentarily actuable by beams of light in coded '.40 position to select one ata time of a group of signalling lines for energization of the selected line, and to maintain energzation of the selected line for a selected period of time.

` It is a further object `of this invention to provide light-responsive units in coded position and actuable by beams of light in coded.` position passing through a film, and to provide means responsive to light to controlmovement of the lm. 50 It is a'further object of thisinvention to provide light-responsive units in coded position and aci-.uabley by beamsvof light inr coded position to energize switches to effect connection of selected current-responsive devices'of a plurality of such deviceswith al source of current, and to provide Itjisa further object of this invention to 'provide light-responsive units in coded position other light-responsive means actuable yto subsequently de-energize said switches. A

Other and further important objects and features of this invention will be apparent from the disclosures in the specication and the` accomy panying drawings.`

vThis invention is illustrated in the drawings and hereinafter more fully described.

-In the drawings:

Figure 1 illustrates diagrammatically the `cirlines shown broken.

Figure 2 illustrates,diagrammatically circuits and instruinentalities` cooperable with the circuits and instrumentalities of Figure 1,.y and with lines shown broken'.

one of a hundred outgoing or signalling linesat a given instant. y A, n

The letter A designates a row of ten sockets of .a units column, in any one of Whiclia lightresponsive unit may be inserted to represent any one o-f the digits from zeroto nine. The letter B designates a row of ten sockets of; a. tens column, in :any one of which a lightresponsive unit' may be inserted to represent any unit of ten from zero 'to ninety.

Thus, a light-responsive unit in position nine of row A, with another light-responsive unit Jin position six of row' B, wouldrepresent the number 69.

Groups or rows, each of ten sockets, and descuits and instrumentalities described below, with A Figure 3 is ashowing cfa portionofl-a nlm `conditioned to permit the passing of light beams therethrough in coded position.

ienated by the letters C, D,E, F, and G, respec- -f tively, provide vfor the insertion of a light-responsive unit in a. given position in each of the 'The light-responsive units are vsources yof current when activated by light, and may be considered as switches closable tol send current over lines to indicate numbers and to qualify the numbers. Thus, if rows A and B alone are used,

. the numbers indicated may vary 'between the limits of zero and 99," but if, in addition to rows A and B, one'of the rows C, D, E, F, and G is madea controlling factor, thesignal transmitted is no longer simply an indication of the position From each socket l0 in row A there is a wire, II connecting the socket with a relay I2, and" each socket is also connected to fav common 'a ground wire I3. When a light-responsive unit'v I4 is inserted in a socket l0 in rowA, and illuminated, it causes current to owthro'ugh arelay 12in dividual to that socket to lrnr'nv'vean armatnrell I to circuit closing position, The armature I5 is connected to a sourcel offci-irrentvlthrougha wire I9, so that movement of the armatureto 'a l a 'selected unit of row B.

circuit closing position results in the connection of 'av wire or Ibus-bar lto'thatsource through a contact I'I o f-tl'1'e'relay;' There'areas many relays #I2 as there are sockets in rowl A to effect yselective connection-of` a bus-bar IB in a'vgroup oftensuch bas-bars indicated generally -bythe numerals i8 for the group. j -5 'l f Itv willbe obvious that single wires'and ground connections Ain-circuit showing is anlexpedient familiar to those engaged in-'theelectricall art to avoid "confusion of lines! f l y v`4fl;Frome'achvsocket I0 in rowl B` there is awire 20 connecting the socket with'a Vrelay 2l, and each'ls'ocket is also connected to? a common groundwire I 3. Wheny a light-'responsiveunit -I 4 luminated, it causes currentto flow through a relayfQZ'Ig" individual to that isocketv-to' move an` armatureZZ-to 'circuit closing position. f-

'Iahe armatureis what is:V conventionally known as a''-gangisvvitch', and when itmoves t0-circuit 'closing position it connects each of the tenbus bars IB of the group I8 to groundthrougha contac't 123 'and afrelay' '24, .eachl wire of lthe group beinglprovide'd witha relay 24 and a contact 23). fSh'ouldlonefof the bus bars I6 be connected through 'an armature iSv-and thewire I9 to a 4source'offour-rent, then-its relay 24 will actuate its armature or line switch 25 tol-engageacontact-26 to' connect an outgoingline 2'! to a source of 1current`28 through a wire 29.r i y 1 To avoid confusionof lines, notall of'lthe `ten gang switches have been fully Vshown with vthe cooperating relays-24 and armatures 25.for connecting an outgoing) line vto thesource of current 28, and it will vbe understood that there lare ten gang switches'and av hundred-relays 24 havingfconta'cts 2G v to lbe Yer'iga-ged'by the armatures `22l of the gang switches,'so that any one yofy one hundredA outgoing lines maybe' selected-fori con'- nectionto the source 28. l 'f'- 1 f t will no w'. bey clear`A that 'if n a vlight-responsive unit is illuminated inA a selected positionl'of row Aand' inA selected` position ,of row, B,fthe gang switch connected to` theu'nit in the ltensv column will movefto vcircuit closing position, but 'since only cne-.flthe relays I2 is capableof eiiecting energigation ofwonly one ofy the wires I6, then only .one of the hundred of relays 24.is. capable ofenergizing one of the hundred outgoinglines. `Ii? an illuminated light-'responsive unit-gis,- in the 4zerozposition ofthetens column, then the gang switch-.shown at the-top of the row of gang..switches..in7' Figure ltwill moveto permit a signal;=to lbesent throughl one of .ten outgoing 'la signal 51;..The vrelays wires, depending upon the position of an illuminated unit yinrow A.

on the other hand, if an illuminated ughtresponsive unit is in the zero position in row A,

kthen ten other outgoingwires are available to indicate that a signal is had from one of the illumina ed units placed` in rowB.

,Onsw

tion

`one hundred outgoing Wires available to indicate from any number combination from wtoibe energized by the ilvidual "trothfefbus bar, and a single line Ais "selected out Vtitten'groups of lines to carry a sig- Jn'all-byfbeing Iselected by one of agroup of ten gangI switches operabler upon the illuminating ofv .a wEach of.l thef; outgoing.-.wires [21 may be' connectedthrougha switch' (Figure 2) to con- :ff

neet-it to. a1 wire-3l vto actuatea relay .S2-and close -a circuitincluding asourcesof` current v33, almfdrivingumotor ofv aY lm 66 in a conven A lInreach rof:-the-colurnns C, 13,111', and irespectively there are ten sockets each-adaptedto ,A

receive alight-responsiveunit, I4 kin any one of ten position sfbut all ofthe sockets in eachrow areconnected to-asingle relay through a switch beenzgiven the numerals 39,j 40, 4I,- 42, andl 4,3,

respectively, and they are adaptedto move armatures 44,5145, 46h41,; and 48,"respectively,which lit-'responsive unit in row Al rfor# tht-,rows D, E, y11', 'and G have' ,v ,i n variously posied, vvone 1n row'A and one'in row B, lthere are ,l

ow be obvious that there are ten busv are connected in series through` a switch 49 toy n |19 .which-is connectedto. all ,.offfthe Aarmatures respectively, toqthebattery )16 throughla wire 55, and a switch -54 is availableto connect the Wire LI9 direct :to thebattery 'I6 when rows A` or f B, :or `lootl-tA'f-and ,B,' are used lwithout reference ,to rows C, D, ELF, 'and-G.'

. ,It willpnow vbe apparent that when switchg54 I is closed, gand selectedflight-responsive unitsin rowsfyA. and-gB are-illuminated, current will flow from the battery IS through oneofgthe` .relays v24 .to.vme x,l e possiblefthe connecting of one of the outgoing lines A21t0,the battery 28 tooperate a currentresponsive device 37, individual to the outgoing lineselected, and to operate also'the relay: 32 l(ligure 2), if one ,of the *switches 30 is closed.-

It will alsonbe'app'arent lthat-by'l suitable'mani ipulation of theswitches 49,50, 5I, .52, and 53, with "switch 5fl'ope`n (Figure 1)', alight unit in onepf thesockets of the rows C, D, E, F, and G must beillurninated to close the-relay individual to" that row"bef.ore`t.he' units in rows A andlB-y are effective to cause a signal to be sent through aselected lin'e"21. p In the operationfof the illustrated switching system, or switchboard, it is contemplated that -flight-responsive units will beplac'ed in rall ofthe 'sockets in rows Aand B to be'swept "by: beams of light positioned. to have numerical significance.

f'as

'arsaooi "A 'movableflmj '(Figure y2) 'may rbe Apla'ce'dbej-` 'tween'a 'source'fof llight' and the'funits in vrows A and `2B`-and conditioned as vindicated iat *6-1 (Eigure "3) fto permit beams of light of varying positio'ns to ysweep the Aunits vof Arows A 'and VB,-so

that the signals going out over the outgoing Llines 'mayfbe translated to repeat the data carried by the film." y

The ,'lrn may carry the record -of lbusiness transactions of oflices Aor agents, 'and 'the nlm is iirs'tpassedtlnroughl a projectionfmachine to indicatethe transactions of a certain agentor ofce, and againpassed through the machine to indicate the transactions of another agent or y o'ice lwith a desired vrow lof the rows C, D, E, F, 'and G arranged effective `to permit the rows Av and VBtc record only the transactions ofthe de-` siredagent'for oce and tor ignore the transac` ftonsof yothers recorded on the same film.

It `is Icontemplated, as shown in Figure 2, that each of 'ther outgoing lines 21 have in circuit.

therewith airelay or gang switch 31 with-an armature movable to connect the illuminated light- `responsive units v55 of a row H of such units to actuate current-responsive' devices 51 lincorpo-Kr `rated a' recording or tabulating -machine in-v 'dicated ygenerally at 15. It is contemplated that thelight units 56 ofthe row H will be scanned by codedlight beams from the lm 55, as described in yconnection with rows A and B,whil`e rowso ,3A and B are -being scanned to translate the sig-y al passing 'over the outgoing wires 21 in terms v of the 'lightun'its 456. Several current-responsive devices v31 may4 be connected in series or in parallel'vcircuit lconnection with 'each outgoing w1re I21 to each operate a ygang switch, with-eachgang switch operably connected with a row of light-responsive vunits to selectively actuate selectedcurrent-responsive devices 51.

Itis ycontemplated that light vbeams passing throug'ha'lm, or other suitablematrix, will illuminate 'selected light-respvo'nsureA units in the rows 'CD,` E, F, and G, the light beams being in vcoded position to identify the work record of a certain agent, for instance.- Rows A andB i groups of elements Aproduced in production 'plants or expended from stock in stock-taking.

For Ia given use, the light-sensitive units in,

selected positions in rows A, B, CyD, E, F, and

G would be steadily illuminated while moving v light beams of coded positions scanned the light units in row H, or in as many'of such .rows .H as arenecessary, to embrace the data carried bythe Hlm-1 f I l The yrelays -I2,2|, and 39 to 43 may be of` the electronic type or of the holding-circuit mag netic type,`and` arranged so that a momentary illuminating of the selected light-responsive units in yrows A to yGr is enough to'fcause the connecting Iof a line 21to `the `source t28 until ythe desireddata onfthe film has been noted by kthe light-responsive units in row' H, and then are returned to 'their unitial 'open ablemeans (not shown). y

l n is wen known that elect-ron relays of the 'arc type w-i-ll maintain the plate `circuit in closed Iswitch 2| 'has been v-rnodified to vshow a metal to the outgoing line" 21.

position by suite `lposition once the laroiis Af-formed 'anduntil some fs'tepis taken toextinguishthe are. v. ,A The'current-responsive device or :gang switch 31 may lbe y'maintained energized after a momentary illumination of zthe lightlresponsive units ofthe rows Ato G by means indicated diagrammatically in Figure 2l In `thecircuit arrangement 'shown in Figure v2,l current in the `line 21 will actuate 'a relay-60 to movean armature i I5l -to vclose a holding circuit which includes the i current-responsive device 31, a holding "coil 62, a Ybattery 63, and the jarmature 64 'of :"a/relay 65.

rThe 'relay 65 isL ncircuit withl contacts of 'the Vgang switch 31 anda light-responsive Aunit 59,

in a vrow J Aof'light-responsive units, Vand illu- *l mination of the light-responsive unit 59 will vre-l sult in lthe Aopening -of the holding #circuit 'and lalso the opening of-'th'e 'circuit of the lmotor 35. 'Thus,

a coded light beam on the nlm may illuminate the Vlight-responsive unit 553 at the end ofa '.'Ellm frun of -desir'edxdata 'to indicate the enjdo'f the 1 The modification illustrated `in connection with row J is for the purpose l'of illustrating vone l Way of inserting lmeans in a line'f21 tohold "the gang switch Av31*energized#until the light-responsive units have been scanned by moving beams of `light'.`|` Electron vtube means 4may 'be connected in lcircuit-,with fthe relays Adirectly actuable `by the light-responsive units in rows A to Gto 'maintain-a selected outgoing 'line 21 energized until the end ofthe-recording or 'ta-b? ulating frun, but the modi'cation `illustrated, in

avoids confusion fof lines, and-is not-to be congstrued as a limitation. l While `the outgoing Aline 21 is shown in Figrure las venergized by .being Aconnected to the l-battery 28 upon the connecting of 'an energized bus bar to ground throughl a 'relay `24 'by Vmovement t o'f a gang switch "22, it "will -be obvious that-current from' thelight-responsive'units y,in row A may be sent vdirectly through the line 21 to actuate a suitable current-responsive device ydirectly or through conventional relay mean-s of the electronic? types, and -as Visillustrated in lthe modgifijed circuitof Fig-ure 4. It is well Aunderstood that many forms off conventional light-respon'- Aspor-isive :units in rows C, YE, Rand G, and the switch 5l! will still exercise thecontrol already' described fully `by means rof a relay 12 effecting control over an armature: v'l`3fand 'a Contact `1l! interposed lin each Wire lil.

With switch 11 or switch 54 clo'sed, Ithe rows vconnection with row J is easier-to illustrate and A 'and 'B maybe used :without 'reference to the rows C, D, E, F, and G, but -with switches "H yand y.r4 open, li1; will be necessary that a' Iiglht- 75 ,responsive l unitf` in a, selectedposition in a sey lected row be lluminatedtoefiect closing ofthe vcircuit between the `light-responsiveunita in row A and the bus bars 'i 6 through the relays 12.

Referring to` Figure l, we have, in substance, what r r1 a ,y be aptly termed, a line-rinden or switchboard, onein which it is possible to cause the energization of any one of a hundred lines by simply activating, by light,1selected light-sensitive units of twenty units, If we were to insert a battery inseries with the wire i3, between the end of the wire and its connection to ground, it is obvious. thatif..rwe l substiizuted manually operable switches for the light-responsive switches shown .in froWsA and B, it would thenbe possible to. energize any selected one of a hundred lines by a lswitchboard having only twenty manually operable switches when a selected pair of switches was Current flowing in a selected line H upon the closing of a switch vin row A causes theclosing of a relay l2 to energize a selected vertical bus bar l6- of ten availabley vertical bars. Current iiowing in a selected line 20 upon the closing of .a `switch in row B will operate a selected gang switch 2l of tenavalablegang switches. Each gang switch may be provided with ten contacts, .insulatedfirom each other, 4 and each connected to an outgoing line individualto each contact,

, and when a gang switch is closed, only oneof 'itscontacts wouldyiind itself in engagement with an energized vertical' bus bar. An alternative, and easier to.. illustrate, is to employ gang switches having a single bar operable to .engage the contacts of ten relays 2d so -thatk the lay of a 'hundred relays 24 which happens to be energized `by one ofgtheten available vertical bus bars.

The circuit of an energized outgoing lline 21 embraces the battery 28, the relay contact 26, the armature 25, and the solenoid o f theaccumulator switch "31.`

It desirable, for certain purposes, to render the yclosing of switches in therows A andBlineffective to energize an outgoing line unless a selected master switch is closed. Rows of switches C, D, E, F, and G are'provided, and these switches may be inserted in series between the'battery 16 and the line I9 which causes energization of the vertical bus bars IB when a relay I2 is closed by a switch in row A. Thus, unless a selected master switch is closed, theA closing of switches in rows A and B, either manuallyor by light, will not result in the selection of an outgoing line.' y

The film frame that carries spots to permit light beams to scan rows A and B tofactuate the lightresponsive switches also carries a spot to` permit light to actuate a master switch` in rows C, D, E, F, and G, and things may be arranged Aso that the'spots indicating numerical values are ineffective to select an outgoing line unless the frame also has a spotin the proper position to actuate the master switch then in use.

Thus, the rows A and B will `in eiect ignore data not falling within a certain classification, which classicationiis determined by the position of the master switch.

Having selected one of ,the hundred outgoing ble to the wheel of the counter.

i'llm may carry other vertical rows vof spots to solenoids of a counter.

lines by means of the lightfresponsiveswitches' of rows A and B, we have also selected which one of a hundred solenoids 31 will be energized to ',move its switch to connect avrowof ten light-` responsive switches to a row of ten key-operating The lm frame that carries spots to result in the actuating of the master switch. and inthe selection of an outgoing line also carries spots to permit the light-sensitive' units 5B toxbe scanned by light to cause the solenoids 51 to transfer to the wheel of the counter the numerical values carried by the spots on the lm.

Thus far, it has been shown that the lin may have a spot in one row to activate the masto activate the line nder, and then spots `'in another row to indicate moneyvalues transfera- Obviously, ythe indicate money values in ascending powersof ten, and thus, when a line 21 is selected, instead of actuating the switch 31 of only onecounter, it may energize several such switches' to make available several counters and their individual rows of light-sensitive devices to transferv to counters money kvaluesof cents, dimes,fan ddo1 lars, for instance. v i

A film may` have thousands of frames, each lcarrying the money values of transactions in different elds. It is obvious that, the film may be run through the projector so -thatonlyfthey money values of a single transaction -f'may be counted. Ona second run through the machine,l

themoney values of an entirely 'different trans,- j action may be recorded.

If the transactions of one lkind lected portion of the lrn and on all of the frames in that portion, with other transactions on a sucplaced in a suitable position, and cause stopping of the motor 35. The operator may then change the position of the masterswitch to'take care of the other transaction whenv the lrn is again started. y

It will now .be clear that, in vthe arrangement illustrated, it is possible to scan a nilm carrying I money values of a hundred different types of transactions in, say,` the life insurance eld, and

ferent groups of adding machines. In the talring of an inventory, a. hundred different Vthings to route these money values toa hundred difhundred diierent adding machines, with the rows A and B automatically routing each itemf vto the yadding machine for that item.

I am aware that many changes may be made and numerous details of construction may be from the principles of this invention, and I,

therefore, do not purpose limiting the patent:` i v` grantedhereon otherwise than necessitated by the prior art. f

I claim as my invention:

1. In combination, a lSource of current, a. plurality of bus bars, a plurality of vsignalling lines each providedwith a line switch actuable by current in a bus bar, a light-responsive unit con-y nected to each of said busbars, and forminga first group of units disposed in coded position, means to selectively illuminate a unit of said group. to elect connection of. a bus bar individual ,1.51- ter` switch, then spots in two other vertical rowsr Lf may have the quantities of each `added on a o.,

'varied through a wide range without departing 'einem .switch connected thereto and Aindividual thereto;

means to selectively illuminate algunit of. 'saidsecj- `ondgroup to eiectmovement,of a gang switch individualto said unit, and thereby eiect movement of vbut one lineswitchfby la", bus fbar` ener,- gized because:y or the illuminatingjor" a unit in said first g'roup,`a.third=gr'ofup @flight-responsive units` interposed'. between s aidsource' yoi energy andsaid bus bars`,'and means to selectively illuminate the'units of said thirdjgroup to effect conltrol of 'current'rilow :from Asaid source to' said bus bars. All v 2`lIn c'onilori'ation,` a plurality of bus bars, a plurality of signalling lines each provided with a rline switch, a light-responsive unit connected to each of said bus bars and forming a rst group of light-responsive units disposed in coded position, 'means to selectively illuminate a unit of said rst group lto effect energization of .a bus bar individual vto said unit, a second group oi light-responsive units disposed in coded position, cachot said second units having a gang switch connected thereto and individual thereto, andl means to selectivelyilluminate a unit of said second group to `effect movement of a gang switch ,individual to said unit to connect one of said lines to a bus bar energized by the illuminating of a unit in said rst group.

3. In combination, a plurality of bus bars, a plurality of signalling lines each provided with a line switch, a light-responsive unit connected to each of said bus bars andforminga rst group of light-responsive units invcoded position, means to selectively illuminate a unit or" said rst group to effect energizationy of a bus bar individual'to that unit, a second group of light-responsive units disposedin coded position, each of said second units having a gang switch connected thereto and individual thereto, vmeans to selectively illuminate a unit of said second group to effect movement of a gang switch individual to said unit to connect one of said lines to a bus bar energized by the illuminating of la unit in said first group, and other light-responsive means in interposed circuit connection between said bus bars and said first group tofcontrolthe energization of said bus bars by said first group.

4. In combination, a plurality of bus bars, a plurality of groups of signalling lines, the members of each group being connectable to a bus bar individual totliat group, .each of said signalling lines being .provided with a line switch, a first group of light-responsive units having units selectively energizabie to energize a bus bar individual to a unit and to a group of said lines, means to selectively illuminate a unit of said iirst groupk of light-responsive units, a second group of light-responsive units having units selectively energizable to energize a switch individual to that unit to effect connection of a selected signalling line to an energized bus bar, and a third lightresponsive means connected with means interposed in series circuit connection with said bus bars to control energization ci said bus bars, and means to selectively illuminate said third light-responsive means.

5. In combination, a currentresponsive switch, means to control actuation of said switch,` said means comprising a line switch connected with A- said current-responsive switch, a bus bar, a first light-responsive unit connected with said bus bar,

means to yilluminate said first light-responsive unit toelect venergization of said buspar, a secondlight-responsive unit,y said line 'switch loeing4 connected with, ,said Asecond light-responsive unit, means to] illun'iinate said second light-responsive'unit to eiect operation of l'said line switch andl theI connecting of said ,current-responsive switch withsaid bus lbar,I circuit holding' 4means actuaple upon momentaryilluminatin'g Iofy one of' said light-responsive units' to maintain said current-responsive,switch in` closed position,` a third light-,responsive unit energizable to effect opening :of said. current-responsive switch, vand means to illuininateiv'sajd third vlight-responsive 6L In combinatie' 'Ja plurality 0f.' Signallingr lines, rn'eans to selecto'ne of said-lines at a time for energizatioinsaid means comprising a plurality of bus bars eacn connectable with a selected group or' said lines, a rrst group of light-responsivev switches in coded `positions and adapted to be selectively illuminated to effect selected energlzation of one of said bus bars, a second group of light-responsive switches in coded positions and adapted to be selectively illuminated to connect one of said lines of a ,groupA to an energized bus bar, means to selectively illuminate said first and said second groups of light-responsive units, means to de-energize the selected energized line, said means comprising a light-responsive switch in circuit `connection therewith and means to illuminate said last-mentioned light-responsive a plurality of bus bars, a rst group of liglit-responsive switches with each switch arranged operable to connect a bus bar individual to a switch 'to said source, a plurality of gang switches, a second group of light-responsive switches with each light-responsive switch of said second group arranged operable to connect a gang switch individual thereto to a plurality of bus bars and to a plurality of lines, and means to selectively illuminate said light-responsive switches.

8. In combination, a hundred signalling cir- -cuits each comprising a line and a return path, a source of current, means to connect a selected one of said hundred lines and its return path to said source of current while excludingthe others of said hundred lines, said means comprising ten bus bars, a first group of ten .lightresponsive switches with each switch arranged operable to connect a bus bar individual to said switch to said source, `ten gang switches, a sec,-`

ond group of light-responsive switches with each light-responsive switch of said second group arranged operable to connect a gang switch individual thereto said ten bus bars and to ten of said hundred lines, and means to selectively illuminate a light-responsive unit in said first group of said light-responsive units and to selectively illuminate a light-responsive unit in said second group of light-responsive* units.

9. In combinatiom'a .source of current, a plurality of signalling lines, means to connect a selected one of said plurality of lines and its return path at a time to said source ci' current while excluding the others of said plurality or lines, said means comprising a plurality of bus bars, a first group oi light-responsive switches with each switch arranged operable to connect a bus bar individual thereto to said source, a plurality of gang switches, asecond group of lightresponsive switches, With eachlight-responsive switch of said second group arranged operable to operate a gang switch individual thereto to connect only a selected one line of said plurality of lines to a bus bar connected to said source, and means to selectively illuminate said light-responsive switches.

10. In combination, a. plurality of signalling lines, a plurality of bus bars, a rst group of light-responsive units disposed in coded position to each other and with each unit arranged connectible to a bus bar individual thereto, a plurality' of gang switches, a second group of lightai'saooi responsive(A vunits 'disposed inf coded position to each other with each unit ofisaid second group arranged connectlble with a gangswitch indi-L vidual thereto for operation of the gang switch to `connect a selected one line to a selectedzfone bus barra source of light, a movable iilm disposed betweensaid ysource of .light and said rst and said second groups of units, said lm being formed whereby a rst beam of light in Acoded position is operable to illuminate a unitin said rst group of units, and vwhereby a second beam of light in coded position Loperable to illumi nate a unit in said second group of funits.

I E. Goonn-- 

